The invention relates to landing gear for the purpose of discharging and landing loads from aircraft, especially from low-flying aircraft. More particularly, the invention is directed to such devices which permit unloading of material and/or personnel from combat aircraft in flight.
It is known to unload cargo including vehicles from flying aircraft by means of one or more parachutes attached to the cargo. This method has certain disadvantages, however, in that it imposes limitations upon the height from which the cargo may be dropped. The minimum height is mainly a function of the time required for the unfolding of the parachute or parachutes, and the subsequent deceleration of the cargo as it approaches the ground. It requires, moreover, a target area free of obstacles that might interfere with the parachutes, and, of course, it is subject to the given wind conditions in the target area.
Another known method of dropping cargo, for instance, motor vehicles and the like from a very low altitude involves pulling the load out of the aircraft by means of a deceleration parachute while the aircraft is flying over the target area at an altitude of a few meters only. Cargo deceleration in a horizontal direction is accomplished by the parachute and surface friction of the cargo on the ground. Owing to the short dropping length, special considerations regarding stabilizing the position of the cargo are not required. However, this method of dropping cargo can be employed only if the target area is free of obstacles in the approach and take-off paths of the aircraft and the distance required for decelerating the load before and after touchdown.
Furthermore, it has been known to reduce the dropping altitude for systems employing parachutes, and to increase the dropping velocity, by using smaller parachutes and by igniting deceleration rockets in the immediate proximity of the ground. Employment of this method has been limited to manned space capsules, and to separate dropping of equipment and personnel, respectively. The area required around the dropping trajectory must, however, be relatively large. Besides, in this known method the target precision is a matter of existing wind conditions.
In accordance with another known method for dropping loads, the load or cargo is drawn out of the aircraft by means of a parachute attached to a rope or cable the length of which approximates the dropping depth whereby the cargo, e.g., a vehicle follows an arcuate path about the deceleration parachute and substantially immediately thereafter touches the ground. The use of this method is limited to cargo as opposed to personnel and may be practiced only where the landing site about the dropping trajectory is larger than in the above mentioned other prior art method. This further known method is also subject to vagaries imposed by wind conditions.